What did Ennis mean when he said..
"I'm gonna tell you this one time, Jack *beep* Twist, an' I ain't foolin'. What I don't know - all them things that I don't know - could get you killed if I come to know them. I ain't jokin"
The way I see it is that if Ennis found out that Jack was sleeping with other man, he would be pissed. Is that what he is trying to say to Jack here?
Ball me Blazer.